SANTA CLARA, Calif. -- San Jose Earthquakes forward Steven Lenhart is expected to be out four to six weeks after having arthroscopic surgery on his right knee.

The Earthquakes made the announcement before Saturday night's game against the Seattle Sounders. The game was the first event at Levi's Stadium, the new $1.2 billion home of the NFL's San Francisco 49ers.

The surgery was performed Friday at Stanford Hospital & Clinics by Dr. Zack Vaughn. Lenhart has appeared in 10 games this season and scored 20 goals since joining San Jose in 2011.